package com.itheima.web.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * 替换HTTPServlet，根据请求的最后一段路径来进行方法分发
 */

public class BaseServlet extends HttpServlet {

    //根据请求的最后一段路径来进行方法分发
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //1.获取请求路径
        String uri = req.getRequestURI();

        //2.获取最后一段路径 方法名
        int index=uri.lastIndexOf('/');
        String methodName= uri.substring(index + 1);

        //2.执行方法
        //2.1获取BrandServlet 字节码对象 Class
        //谁调用我（this所在的方法）我（this）代表谁
        //System.out.println(this);

        Class<? extends BaseServlet> cls = this.getClass();
        //2.2获取Method方法对象
        try {
            Method method = cls.getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
            //2.3执行方法
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }

    }
}
